tgamma(3) Library Functions Manual tgamma(3) tgamma, tgammaf, tgammal - (libm -lm) #include double tgamma(double x); float tgammaf(float x); long double tgammal(long double x); glibc ( feature_test_macros(7)): tgamma() tgammaf() tgammal(): _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L x. Gamma(x) = 0 t^(x-1) e^-t dt . m Gamma(m+1) = m! x: Gamma(x+1) = x * Gamma(x) x : Gamma(x) * Gamma(1 - x) = PI / sin(PI * x) Gamma(x). x (NaN) NaN. x . x NaN. HUGE_VAL HUGE_VALF HUGE_VALL . 0 . x -0 +0 HUGE_VAL HUGE_VALF HUGE_VALL . math_error(7) . : : x errno EDOM. (FE_INVALID) ( ). : x +0 -0 errno ERANGE. (FE_DIVBYZERO). : errno ERANGE. (FE_OVERFLOW). glibc C99 POSIX.1-2001. : (FE_UNDERFLOW) errno ERANGE. attributes(7). +------------+------------------------------------+--------------------+ || | | +------------+------------------------------------+--------------------+ |tgamma(), | | MT-Safe | |tgammaf(), | | | |tgammal() | | | +------------+------------------------------------+--------------------+ C11, POSIX.1-2008. glibc 2.1. C99 POSIX.1-2001. " " gamma(3) ( gamma(3) ). glibc 2.18 glibc errno EDOM x . glibc 2.19 glibc errno ERANGE . glibc 2.3.3 +0 -0 ( errno EDOM FE_INVALID) . gamma(3) lgamma(3) 3 . . : . 6.18 8 2026 tgamma(3)